The invention relates to an airbag apparatus that protects an occupant by inflating and deploying an airbag at a position close to the occupant seated in a vehicle seat.
An airbag apparatus is provided with an airbag and an inflator that generates inflation gas for inflating the airbag. In recent years, a proposal to partition inside of the airbag with a plurality of inflation portions, and respectively adjust internal pressure in those inflation portions has been made.
For example, in an airbag apparatus described in Japanese Laid-Open Patent Publication No. 2012-30614, inside of an airbag is partitioned into an upstream inflation portion and a downstream inflation portion by a partitioning member. Inflation gas is directly supplied to the upstream inflation portion from an inflator, and the inflation gas is supplied to the downstream inflation portion via the upstream inflation portion. Further, the partitioning member is provided with a pressure regulating valve that adjusts the flow rate of the inflation gas flowing into the downstream inflation portion from the upstream inflation portion. The pressure regulating valve has such a structure that it opens when the airbag is inflated and restrains an occupant. That is, the pressure regulating valve opens by utilizing reduction of tension on the partitioning member caused by the partitioning member being bent by an external force applied to the airbag accompanying the restraint of the occupant by the airbag. In the apparatus described in Japanese Laid-Open Patent Publication No. 2012-30614, in order to realize the pressure regulating valve to open for sure, the pressure regulating valve is arranged at a portion where the external force becomes the largest (specifically, a center portion of the partitioning member).